Add cc_library for ScopedMockLog

[calder]

As far as I can tell there is currently no way of using ScopedMockLog from Bazel.

[drigz]

@calder It shouldn't be too hard to add this. It will add a dependency on googletest, but hopefully only when ScopedMockLog is actually used.

Can you point me to some code that uses ScopedMockLog so I can check it's being made available correctly?

[calder]

@drigz: Building and running src/mock-log_test.cc under Bazel should be a pretty good test.

[drigz]

Would external users expect to include it with #include "mock-log.h" or with #include <glog/mock-log.h>? (or something else??)

[calder]

Probably #include <glog/mock-log.h>.

[drigz]

On further investigation, this isn't easy to do, since mock-log.h is not written the way the public headers are. To make it work without breaking anything else I think we'd need to move mock-log.h to src/glog/mock-log.h.in and template the namespace into it.

An easier way to use ScopedMockLog with Bazel would be to vendor it into your own project and hardcode the namespace instead of including utilities.h.